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experiencelifemag.com
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The Secret Lives of Fruits & Veggies
Do you think of apples, peaches, cucumbers and red peppers as inert, lifeless objects? Take a closer look at the magical inner workings of fruits and vegetables, and you’ll never see them quite the same way again.
By Catherine Guthrie |
April 2009 |
Living, Breathing, Choosing, Responding
Complex Biological Entities
Hormonal Fluctuations
Sensitive and Vulnerable to Bruising
Flexible Rate of Aging
Responsive to Nature and Nurture
Fruit-Bowl Wisdom
They’re prone to bumps and bruises, they’re sensitive and picky, and they
crave TLC. No, we’re not talking about touchy toddlers; we’re talking about
fruits and vegetables — living, breathing entities that, as it turns out, are
nearly as vital and complex as we are. They have quirks and quibbles,
preferences and personalities. They have circadian rhythms, they bruise when
mishandled and pant in the heat. Much like people, each has a complex internal
chemistry and a limited lifespan. And by the time most fruits and vegetables
make their produce aisle debut, they’re in the twilight of their
lives. “People need to understand that fruits and vegetables are not
manufactured, static items,” says Russ Parsons, the food editor and columnist
for the Los Angeles Times and author of How to Pick a Peach: The Search for
Flavor from Farm to Table (Houghton Mifflin, 2008). “They develop and adapt and
age just like the rest of us.” How fruits and veggies live — how they are
raised and nurtured and handled — dramatically affects the flavor and nutrients
we can hope to reap from them. Here’s a glimpse into some of their mysterious
inner workings. Chances are, you have more in common with the contents of your
crisper than you think.
Living, Breathing, Choosing, Responding
At every stage of their existence
— from conception, maturity and ripening, to shipping, retailing and composting
— fruits and vegetables are undergoing myriad and magical biological and
chemical processes in response to their environments. As Peter Tompkins and
Christopher Bird report in their 1973 classic, The Secret Life of Plants,
“Plants move their bodies as freely, easily and gracefully as the most skilled
animal or human, and . . . the only reason we don’t appreciate the fact is that
plants do so at a much slower pace than humans.” Plants, they add, “are capable
of intent: They can stretch toward, or seek out, what they want in ways as
mysterious as the most fantastic creations of romance.” Indeed, fruits and
vegetables constantly make choices that determine what they will become. Left to
their own devices, for example, plants will do everything in their power to
satisfy their basic need for sun and water — following the sun with their
branches, tilting their leaves to catch light or water, and pushing their roots
down and out into the soil in search of nutrients. And it doesn’t stop
there. Plants react to everything, including the wind, temperature, soil and
stars, says Gunther Hauk, a biodynamic farmer in Illinois and author of Toward
Saving the Honeybee (Rudolph Steiner Press, 2003). For instance, Hauk has found
that seeds sown three days before a full moon have a much higher germination
rate than seeds sown three days before a new moon. For this he credits the
moon’s fertility. It may sound a little woo-woo until you consider that just as
the moon exerts a tidal pull on water in the ocean, it also affects the water
and waterborne nutrients stored in the soil and in plants’ bodies. So it makes
sense that the level of soil-stored nutrients available to a plant at a given
time is directly related to the stage of the lunar cycle, and that plants
respond accordingly. (For more on the intimate relationship between plants
and the soil in which they’re grown, see “Good Earth” in the October 2008
archives.)
Complex Biological Entities
All plants have meristematic cells that are
much like the stem cells in people, says Preston Andrews, PhD, professor of
horticulture at Washington State University in Pullman, Wash. Meristematic
cells, found in meristem tissue, are undifferentiated, meaning they can morph
into flowers, fruits, roots or whatever the plant may need. “When you remove
a tip or shoot you remove that meristem tissue, so the plant responds by
replacing what was taken,” explains Andrews. Plants also have skeletons,
made of cellulose instead of bone. Cellulose is Mother Nature’s modeling clay.
It takes any form she dreams up, from the bell-shaped flesh of a red pepper to a
crunchy stalk of celery. Cellulose has a hollow, matrix-like structure that’s
both strong and flexible. Its strength helps it resist hailstorms and wind
gusts. Its honeycombed walls protect the delicate fluid-filled vacuoles
within. Like nutrient-rich piñatas, these vacuoles hold the secret ingredients
to each individual fruit’s flavor and aroma. But plants are much more than
just cellulose and water. Floating within each cell is a brew of compounds that
lends fruits and veggies everything from flavor, smell and color to antioxidants
and phytonutrients. One of the most important is chlorophyll, the chemical that
makes plants green. Responsible for absorbing sunlight for photosynthesis, the
chemical constituents of chlorophyll are similar to the heme structure of
hemoglobin in human blood. And once ingested by humans, they act as powerful
detoxifiers of our blood and tissues.
Hormonal Fluctuations
Not unlike humans, edible plants owe their aging, or
ripening, to a surge of hormones. But, rather than depending on testosterone and
estrogen, plants rely on ethylene to come of age. A powerful plant hormone,
ethylene triggers cell walls — once rigid with cellulose — to soften, and it
also dissolves pectin, the glue holding plant cells together. Once broken down
in this way, the pliable and permeable cell walls invite the mingling of
compounds that create a fruit’s juice as well as soften its skin. Inside a
ripening fruit, the complexity of flavor increases. Its flesh naturally sweetens
as simple sugars (glucose) morph into more complex versions of themselves
(fructose and sucrose). “Ripeness is not a fixed point, but a process,” says
Parsons. “It begins with pollinated flowers forming fruit, and it ends with
rot.” That’s why being sensitive to a plant’s lifecycle can help you take
advantage of fruits’ peak moments of taste and nutrition — and avoid a soggy,
fly-infested fruit bowl. Vegetables ripen in a slower, more controlled,
manner. Thanks to their slowpoke ways, they also live longer. And, unlike fruit,
their flavor (and many times their smell) is released only when their cells are
crushed (or collapsed during cooking). “You have to break the cells to get the
nutrient value out,” says Stephen Goff, PhD, a plant biologist at the University
of Arizona, Tucson. The necessary destruction allows for neighboring enzymes to
cohabitate in new ways. For instance, what’s more boring than an onion?But cut
one open and a dizzying array of chemical reactions takes place — some of which
can literally bring tears to a cook’s eyes. Ushering vegetables into maturity
is relatively straightforward, but ripening fruits is tricky business. Some
fruits, like berries and cherries, refuse to ripen at all once they are removed
from their parent plants. Others, like tomatoes and pears, are happy to be
plucked green and need nothing more than a sunny windowsill to divulge their
innermost secrets. This fickleness is a formidable hurdle for growers
who want to get their produce to consumers at the height of flavor. Some
producers actually blast their fruit with ethylene gas at the warehouse to force
it to ripen on demand. But, while ripening with ethylene gas will cause fruit to
soften and change color, it can’t add sugar or any of the other chemicals that
add up to a complex flavor, explains Parsons. “Picked at just the right moment
and ripened this way, a tomato can be adequate, but it will never be
great.” You can, however, use ethylene gas at home to gently speed the
ripening process with good results. Try it with pears, which you can safely buy
green and bring to perfection on the countertop. If you’re in a hurry, place a
few pears in a paper bag and fold the top down. The bag traps the fruit’s
ethylene gas and accelerates ripening. To avoid accidentally speeding
ripening (and rotting), separate ethylene-producing fruit, like apples and
avocados, from non-ethylene-producing fruit and vegetables, like bananas and
leafy greens. (For more fruit and vegetable storage tips, see “Fruit-Bowl
Wisdom,” below.)
Sensitive and Vulnerable to Bruising
Harvesting delicate fruit without
damaging it is hard enough; add a cross-country trek to the mix and the
challenges multiply. Like human skin, plant skin is vulnerable to infection. The
smallest nick or puncture wound on the surface can become a festering sore.
Yeasts and molds lurking on the surface speed to the cut to feast on whatever
juices, sugars and organic acids leak out. Cuts can also lead to enzymatic
browning. Most produce — especially apples, pears, bananas and artichokes —
contains substances that, when exposed to oxygen, change the color of the flesh
to brown. The browning itself doesn’t affect the taste or nutrients so much as
appearance, but few people would choose brown-tinged fruit over a fresh-fleshed
sibling — in part because we’ve come to associate browning with other types of
damage (such as bruising, molding and fermenting), which do affect taste. But
surface nicks aren’t a fruit’s only worry. Just as human tissues bruise when
manhandled, too much pressure can bruise delicate produce, squashing cell walls
and sending fluids flooding into damaged tissue. Unlike people, though, produce
can’t repair the damage. Instead, a bad bruise simultaneously accelerates both
ripening and dehydration, which can lead to premature death. One bad bruise
quadruples the rate at which apples lose water. Even the vibrations created
by trucking produce cross-country can cause problems. Vine-ripened tomatoes, for
instance, must be carefully packaged to ensure the gel around the seeds isn’t
shaken to the point that it falls right out of the fruit the moment it’s cut,
says James Gorny, PhD, executive director of the Postharvest Technology Research
and Information Center at the University of California at Davis. In fact, he
notes that upward of 25 percent of all fruits and vegetables picked in the
United States are never eaten because they are lost to such damage. But rough
handling doesn’t just make for less attractive produce, it also lowers the
nutrient content of certain fruits. Vitamin C is especially vulnerable. Because
a bruise damages cellular and tissue structure, it can also disrupt a fruit’s
delicate chemical balance. For instance, a bruised tomato quickly loses roughly
15 percent of its vitamin C.
Flexible Rate of Aging
With their delicate hormones, skin and water needs,
it’s no wonder that fruits and veggies must be raced to market. “Most fruits are
never going to be any better than the first day you pick them off the vine,”
says Gorny. “There is nothing we can do to enhance quality — it’s all about
preventing decay.” As a result, skilled handlers have developed several tricks
to fool fruit into aging gracefully. One way is to keep them cool. Like
people, fruits and vegetables need to breathe. But their breathing rate is
linked to temperature. When they get hot or physically taxed, they “pant,”
increasing their rate of respiration and gas exchange much as we do when
overheated. Similarly, fruits’ and veggies’ breathing slows as they cool down.
That’s a good thing, because as they breathe, they use energy, just like us.
Unlike us, however, they can’t reach for a snack to replenish low energy stores;
instead they are forced to break down their complex parts (starch, sugars and
organic acids) into simpler molecules, and those parts are what gives them their
flavor. Essentially, the less fruits and veggies breathe, the more flavor
they retain. (Interestingly, not all produce breathes at the same rate:
Asparagus, broccoli, mushrooms and peas breathe 10 times faster than apples,
cabbage, lemons and tomatoes.) Take care in how much you restrict
respiration, though: Chill a fruit too much and you’ll destroy enzymes necessary
for ripening. “If you’ve ever bitten into a mealy, dry peach, it’s because
something went wrong during ripening, storage or transport,” says Gorny. “Most
likely the enzymes involved in the softening process, which results in sweeter,
juicier fruit, were broken by exposure to too-cold temperatures.”
Temperature also tells a plant when to turn starch into sugar. A plant’s
starch is like a person’s stored fat — energy saved for a rainy day. Similarly,
plant sugar is like ours in that it’s used as quick fuel. Vegetables are
typically higher in starch (think potatoes, carrots and beets), but cooking them
softens their structure and invites a sweetness that comes more naturally to
fruit. As fruits ripen, enzymes turn starch into sugar. Bananas are a perfect
example. At cool temperatures, they stay green. If you’ve ever bitten into a
green banana, it tastes starchy. But when bananas are left on the countertop to
ripen, not only is the starch converted to sugar but the chlorophyll also breaks
down to reveal the fruit’s underlying bright yellow jacket. “It’s a complex
chemical ballet,” says Gorny. Get a banana at just the right moment and you
enjoy a lovely array of floral aromas and a firm, creamy texture. Wait too long,
of course, and you end up with a bland, grayish mush. A similar type of
starch-sugar conversion happens in potatoes, with different but equally
dramatic consequences. Chill potatoes and they convert some of their starch to
sugar. “That’s fine if you want them sweet,” Gorny says, “but try to make French
fries out of them and that excess sugar turns them either black or brown.” Which
is why potatoes are best stored in a cool and dark, but not cold, location.
Responsive to Nature and Nurture
The breeding and developmental
environment a farmer gives a plant can make an immense difference in its
quality, but so can the TLC it receives long past the harvest. Just as
children can’t escape the influence of their acquaintances and educators, a
fruit’s or vegetable’s personality — measured by its depth of flavor and breadth
of nutrients — is shaped by the caring hands of subsequent handlers. And that
includes everyone from the produce manager and baggers at your market to you and
anyone else who handles your food at home. “The baggers at the store think
I’m a fussy person for insisting they treat my produce gently,” says Lynn
Gordon, founder of French Meadow Bakery and Café in Minneapolis, “but it’s easy
to bruise, and therefore I treat it lovingly all the way to my refrigerator and
beyond.” When traveling between the store and home, Gordon gives her fresh
produce the same care and attention she gives her fragile eggs. And when she’s
preparing a meal at home or at her restaurant, Gordon takes special steps to
honor the complexity of the fruits and vegetables she’s about to turn into food.
She makes sure to have plenty of beautiful bowls and colanders on hand to
receive the fresh produce. She keeps her kitchen spotless, her knives sharp,
and she makes sure she’s feeling relaxed as she cooks to keep the food’s energy
from becoming contaminated by stress. “Every step, from the field to the
plate, should have an energy of reverence, acknowledgement and consciousness,”
says Gordon. “That’s what makes good cooking great.” When so much of the food
we buy is packaged in cardboard and plastic, it can be easy to forget much of it
originally came from living plants. (Try emptying a package of instant oatmeal
into a bowl and visualizing the graceful stalks of grain that gave way to the
powdery pile. It’s a stretch.) Still, while so much of what’s found in the
grocery store is the food equivalent of the morgue, the produce aisle is
nature’s reminder that food is synonymous with life. Take one look at its bright
red apples or chubby purplish-black eggplants, and the magical
transformation of energy from sun to plants to people is undeniable. Whether
you appreciate produce for the long path it has traveled, for the amazing and
complex science it represents, for the consciousness it embodies, or simply
for the nutritious and delicious eating experience it delivers, once you
understand what the lifecycle of edible plants involves, it’s tough to look at
fruits and vegetables without at least a little newfound respect.
Catherine Guthrie is contributing editor of Experience Life.
Fruit-Bowl Wisdom
How to properly store fruits and veggies at home. By the time fruits and veggies make it to your kitchen, they’re pretty much
in the twilight of their lives, so it’s very important to store them properly.
Some fruits and vegetables are safe to refrigerate; others should be stored on
the countertop to protect the delicate ripening enzymes. Whether they’re stored
in the fridge or on the counter, remember to keep ethylene producers (see Web
Extra! at the top right of this page) away from ripe fruits and mature vegetables so you don’t accelerate
aging. And, since moisture speeds decay, don’t wash fruits and vegetables until
you’re ready to eat them. Put paper towels between layers of berries to extend
storage time. Get more tips in “Handle With Care” in the May 2005 archives. ROOM TEMPERATURE
Store at room temperature — on the counter, in the pantry or in a drawer — and
use while fresh.
Fruits
Apples (less than 7 days),
bananas, grapefruit, lemons, limes, mandarins, mangoes, melons, oranges,
papayas, persimmons, pineapple, plantain, pomegranates, watermelons Vegetables
Basil (stems in
water), cukes+, eggplants+, garlic*, ginger, jicama, onions*, peppers
+, potatoes*, pumpkins, sweet potatoes*, tomatoes, winter squashes * Store in a well-ventilated area in the pantry. Protect potatoes from light
to avoid greening. + Can be kept in the refrigerator for one to three days, if used soon after
removal.
COUNTER TO FRIDGE
These fruits will ripen gradually on the counter, but don’t do well in
fridge for long. Refrigerate only when ripe or if cut, and not for more than a
day or two.
Fruits
Avocados,
kiwi, nectarines, peaches, pears, plums, plumcots
REFRIGERATOR
These foods spoil quickly unless kept cool. But take care not to over-cool your
fridge. Icy temperatures hasten fruits’ and veggies’ demise.
Fruits
Apples,
apricots, Asian pears, all berries, cherries, figs, grapes Vegetables
Artichokes,
asparagus, green beans, lima beans, beets, Belgian endive, broccoli, Brussels
sprouts, cabbage, carrots, cauliflower, celery, green onions,
herbs (except basil), leafy greens, leeks, lettuce, mushrooms, peas, radishes,
spinach, sprouts, summer squash, sweet corn Reproduced from Storing Fresh
Fruits and Vegetables for Better Taste by Adel
Kader,
PhD, Jim Thompson, PhD, and Kathi Sylva, PhD, University of California,
Davis, Postharvest Technology Research and Information Center, 2000.
Printed
with permission of Adel Kader, PhD.
For a detailed list of ethylene producers and ethylene-sensitive fruits and
vegetables, see the Web Extra! at the top right of this page.
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The Secret Lives of Fruits & Veggies
Do you think of apples, peaches, cucumbers and red peppers as inert, lifeless objects? Take a closer look at the magical inner workings of fruits and vegetables, and you’ll never see them quite the same way again.
By Catherine Guthrie | Features,
April 2009 |
Living, Breathing, Choosing, Responding
Complex Biological Entities
Hormonal Fluctuations
Sensitive and Vulnerable to Bruising
Flexible Rate of Aging
Responsive to Nature and Nurture
Fruit-Bowl Wisdom
They’re prone to bumps and bruises, they’re sensitive and picky, and they
crave TLC. No, we’re not talking about touchy toddlers; we’re talking about
fruits and vegetables — living, breathing entities that, as it turns out, are
nearly as vital and complex as we are. They have quirks and quibbles,
preferences and personalities. They have circadian rhythms, they bruise when
mishandled and pant in the heat. Much like people, each has a complex internal
chemistry and a limited lifespan. And by the time most fruits and vegetables
make their produce aisle debut, they’re in the twilight of their
lives. “People need to understand that fruits and vegetables are not
manufactured, static items,” says Russ Parsons, the food editor and columnist
for the Los Angeles Times and author of How to Pick a Peach: The Search for
Flavor from Farm to Table (Houghton Mifflin, 2008). “They develop and adapt and
age just like the rest of us.” How fruits and veggies live — how they are
raised and nurtured and handled — dramatically affects the flavor and nutrients
we can hope to reap from them. Here’s a glimpse into some of their mysterious
inner workings. Chances are, you have more in common with the contents of your
crisper than you think.
Living, Breathing, Choosing, Responding (Back to Top)
At every stage of their existence
— from conception, maturity and ripening, to shipping, retailing and composting
— fruits and vegetables are undergoing myriad and magical biological and
chemical processes in response to their environments. As Peter Tompkins and
Christopher Bird report in their 1973 classic, The Secret Life of Plants,
“Plants move their bodies as freely, easily and gracefully as the most skilled
animal or human, and . . . the only reason we don’t appreciate the fact is that
plants do so at a much slower pace than humans.” Plants, they add, “are capable
of intent: They can stretch toward, or seek out, what they want in ways as
mysterious as the most fantastic creations of romance.” Indeed, fruits and
vegetables constantly make choices that determine what they will become. Left to
their own devices, for example, plants will do everything in their power to
satisfy their basic need for sun and water — following the sun with their
branches, tilting their leaves to catch light or water, and pushing their roots
down and out into the soil in search of nutrients. And it doesn’t stop
there. Plants react to everything, including the wind, temperature, soil and
stars, says Gunther Hauk, a biodynamic farmer in Illinois and author of Toward
Saving the Honeybee (Rudolph Steiner Press, 2003). For instance, Hauk has found
that seeds sown three days before a full moon have a much higher germination
rate than seeds sown three days before a new moon. For this he credits the
moon’s fertility. It may sound a little woo-woo until you consider that just as
the moon exerts a tidal pull on water in the ocean, it also affects the water
and waterborne nutrients stored in the soil and in plants’ bodies. So it makes
sense that the level of soil-stored nutrients available to a plant at a given
time is directly related to the stage of the lunar cycle, and that plants
respond accordingly. (For more on the intimate relationship between plants
and the soil in which they’re grown, see “Good Earth” in the October 2008
archives.)
Complex Biological Entities (Back to Top)
All plants have meristematic cells that are
much like the stem cells in people, says Preston Andrews, PhD, professor of
horticulture at Washington State University in Pullman, Wash. Meristematic
cells, found in meristem tissue, are undifferentiated, meaning they can morph
into flowers, fruits, roots or whatever the plant may need. “When you remove
a tip or shoot you remove that meristem tissue, so the plant responds by
replacing what was taken,” explains Andrews. Plants also have skeletons,
made of cellulose instead of bone. Cellulose is Mother Nature’s modeling clay.
It takes any form she dreams up, from the bell-shaped flesh of a red pepper to a
crunchy stalk of celery. Cellulose has a hollow, matrix-like structure that’s
both strong and flexible. Its strength helps it resist hailstorms and wind
gusts. Its honeycombed walls protect the delicate fluid-filled vacuoles
within. Like nutrient-rich piñatas, these vacuoles hold the secret ingredients
to each individual fruit’s flavor and aroma. But plants are much more than
just cellulose and water. Floating within each cell is a brew of compounds that
lends fruits and veggies everything from flavor, smell and color to antioxidants
and phytonutrients. One of the most important is chlorophyll, the chemical that
makes plants green. Responsible for absorbing sunlight for photosynthesis, the
chemical constituents of chlorophyll are similar to the heme structure of
hemoglobin in human blood. And once ingested by humans, they act as powerful
detoxifiers of our blood and tissues.
Hormonal Fluctuations (Back to Top)
Not unlike humans, edible plants owe their aging, or
ripening, to a surge of hormones. But, rather than depending on testosterone and
estrogen, plants rely on ethylene to come of age. A powerful plant hormone,
ethylene triggers cell walls — once rigid with cellulose — to soften, and it
also dissolves pectin, the glue holding plant cells together. Once broken down
in this way, the pliable and permeable cell walls invite the mingling of
compounds that create a fruit’s juice as well as soften its skin. Inside a
ripening fruit, the complexity of flavor increases. Its flesh naturally sweetens
as simple sugars (glucose) morph into more complex versions of themselves
(fructose and sucrose). “Ripeness is not a fixed point, but a process,” says
Parsons. “It begins with pollinated flowers forming fruit, and it ends with
rot.” That’s why being sensitive to a plant’s lifecycle can help you take
advantage of fruits’ peak moments of taste and nutrition — and avoid a soggy,
fly-infested fruit bowl. Vegetables ripen in a slower, more controlled,
manner. Thanks to their slowpoke ways, they also live longer. And, unlike fruit,
their flavor (and many times their smell) is released only when their cells are
crushed (or collapsed during cooking). “You have to break the cells to get the
nutrient value out,” says Stephen Goff, PhD, a plant biologist at the University
of Arizona, Tucson. The necessary destruction allows for neighboring enzymes to
cohabitate in new ways. For instance, what’s more boring than an onion?But cut
one open and a dizzying array of chemical reactions takes place — some of which
can literally bring tears to a cook’s eyes. Ushering vegetables into maturity
is relatively straightforward, but ripening fruits is tricky business. Some
fruits, like berries and cherries, refuse to ripen at all once they are removed
from their parent plants. Others, like tomatoes and pears, are happy to be
plucked green and need nothing more than a sunny windowsill to divulge their
innermost secrets. This fickleness is a formidable hurdle for growers
who want to get their produce to consumers at the height of flavor. Some
producers actually blast their fruit with ethylene gas at the warehouse to force
it to ripen on demand. But, while ripening with ethylene gas will cause fruit to
soften and change color, it can’t add sugar or any of the other chemicals that
add up to a complex flavor, explains Parsons. “Picked at just the right moment
and ripened this way, a tomato can be adequate, but it will never be
great.” You can, however, use ethylene gas at home to gently speed the
ripening process with good results. Try it with pears, which you can safely buy
green and bring to perfection on the countertop. If you’re in a hurry, place a
few pears in a paper bag and fold the top down. The bag traps the fruit’s
ethylene gas and accelerates ripening. To avoid accidentally speeding
ripening (and rotting), separate ethylene-producing fruit, like apples and
avocados, from non-ethylene-producing fruit and vegetables, like bananas and
leafy greens. (For more fruit and vegetable storage tips, see “Fruit-Bowl
Wisdom,” below.)
Sensitive and Vulnerable to Bruising (Back to Top)
Harvesting delicate fruit without
damaging it is hard enough; add a cross-country trek to the mix and the
challenges multiply. Like human skin, plant skin is vulnerable to infection. The
smallest nick or puncture wound on the surface can become a festering sore.
Yeasts and molds lurking on the surface speed to the cut to feast on whatever
juices, sugars and organic acids leak out. Cuts can also lead to enzymatic
browning. Most produce — especially apples, pears, bananas and artichokes —
contains substances that, when exposed to oxygen, change the color of the flesh
to brown. The browning itself doesn’t affect the taste or nutrients so much as
appearance, but few people would choose brown-tinged fruit over a fresh-fleshed
sibling — in part because we’ve come to associate browning with other types of
damage (such as bruising, molding and fermenting), which do affect taste. But
surface nicks aren’t a fruit’s only worry. Just as human tissues bruise when
manhandled, too much pressure can bruise delicate produce, squashing cell walls
and sending fluids flooding into damaged tissue. Unlike people, though, produce
can’t repair the damage. Instead, a bad bruise simultaneously accelerates both
ripening and dehydration, which can lead to premature death. One bad bruise
quadruples the rate at which apples lose water. Even the vibrations created
by trucking produce cross-country can cause problems. Vine-ripened tomatoes, for
instance, must be carefully packaged to ensure the gel around the seeds isn’t
shaken to the point that it falls right out of the fruit the moment it’s cut,
says James Gorny, PhD, executive director of the Postharvest Technology Research
and Information Center at the University of California at Davis. In fact, he
notes that upward of 25 percent of all fruits and vegetables picked in the
United States are never eaten because they are lost to such damage. But rough
handling doesn’t just make for less attractive produce, it also lowers the
nutrient content of certain fruits. Vitamin C is especially vulnerable. Because
a bruise damages cellular and tissue structure, it can also disrupt a fruit’s
delicate chemical balance. For instance, a bruised tomato quickly loses roughly
15 percent of its vitamin C.
Flexible Rate of Aging (Back to Top)
With their delicate hormones, skin and water needs,
it’s no wonder that fruits and veggies must be raced to market. “Most fruits are
never going to be any better than the first day you pick them off the vine,”
says Gorny. “There is nothing we can do to enhance quality — it’s all about
preventing decay.” As a result, skilled handlers have developed several tricks
to fool fruit into aging gracefully. One way is to keep them cool. Like
people, fruits and vegetables need to breathe. But their breathing rate is
linked to temperature. When they get hot or physically taxed, they “pant,”
increasing their rate of respiration and gas exchange much as we do when
overheated. Similarly, fruits’ and veggies’ breathing slows as they cool down.
That’s a good thing, because as they breathe, they use energy, just like us.
Unlike us, however, they can’t reach for a snack to replenish low energy stores;
instead they are forced to break down their complex parts (starch, sugars and
organic acids) into simpler molecules, and those parts are what gives them their
flavor. Essentially, the less fruits and veggies breathe, the more flavor
they retain. (Interestingly, not all produce breathes at the same rate:
Asparagus, broccoli, mushrooms and peas breathe 10 times faster than apples,
cabbage, lemons and tomatoes.) Take care in how much you restrict
respiration, though: Chill a fruit too much and you’ll destroy enzymes necessary
for ripening. “If you’ve ever bitten into a mealy, dry peach, it’s because
something went wrong during ripening, storage or transport,” says Gorny. “Most
likely the enzymes involved in the softening process, which results in sweeter,
juicier fruit, were broken by exposure to too-cold temperatures.”
Temperature also tells a plant when to turn starch into sugar. A plant’s
starch is like a person’s stored fat — energy saved for a rainy day. Similarly,
plant sugar is like ours in that it’s used as quick fuel. Vegetables are
typically higher in starch (think potatoes, carrots and beets), but cooking them
softens their structure and invites a sweetness that comes more naturally to
fruit. As fruits ripen, enzymes turn starch into sugar. Bananas are a perfect
example. At cool temperatures, they stay green. If you’ve ever bitten into a
green banana, it tastes starchy. But when bananas are left on the countertop to
ripen, not only is the starch converted to sugar but the chlorophyll also breaks
down to reveal the fruit’s underlying bright yellow jacket. “It’s a complex
chemical ballet,” says Gorny. Get a banana at just the right moment and you
enjoy a lovely array of floral aromas and a firm, creamy texture. Wait too long,
of course, and you end up with a bland, grayish mush. A similar type of
starch-sugar conversion happens in potatoes, with different but equally
dramatic consequences. Chill potatoes and they convert some of their starch to
sugar. “That’s fine if you want them sweet,” Gorny says, “but try to make French
fries out of them and that excess sugar turns them either black or brown.” Which
is why potatoes are best stored in a cool and dark, but not cold, location.
Responsive to Nature and Nurture (Back to Top)
The breeding and developmental
environment a farmer gives a plant can make an immense difference in its
quality, but so can the TLC it receives long past the harvest. Just as
children can’t escape the influence of their acquaintances and educators, a
fruit’s or vegetable’s personality — measured by its depth of flavor and breadth
of nutrients — is shaped by the caring hands of subsequent handlers. And that
includes everyone from the produce manager and baggers at your market to you and
anyone else who handles your food at home. “The baggers at the store think
I’m a fussy person for insisting they treat my produce gently,” says Lynn
Gordon, founder of French Meadow Bakery and Café in Minneapolis, “but it’s easy
to bruise, and therefore I treat it lovingly all the way to my refrigerator and
beyond.” When traveling between the store and home, Gordon gives her fresh
produce the same care and attention she gives her fragile eggs. And when she’s
preparing a meal at home or at her restaurant, Gordon takes special steps to
honor the complexity of the fruits and vegetables she’s about to turn into food.
She makes sure to have plenty of beautiful bowls and colanders on hand to
receive the fresh produce. She keeps her kitchen spotless, her knives sharp,
and she makes sure she’s feeling relaxed as she cooks to keep the food’s energy
from becoming contaminated by stress. “Every step, from the field to the
plate, should have an energy of reverence, acknowledgement and consciousness,”
says Gordon. “That’s what makes good cooking great.” When so much of the food
we buy is packaged in cardboard and plastic, it can be easy to forget much of it
originally came from living plants. (Try emptying a package of instant oatmeal
into a bowl and visualizing the graceful stalks of grain that gave way to the
powdery pile. It’s a stretch.) Still, while so much of what’s found in the
grocery store is the food equivalent of the morgue, the produce aisle is
nature’s reminder that food is synonymous with life. Take one look at its bright
red apples or chubby purplish-black eggplants, and the magical
transformation of energy from sun to plants to people is undeniable. Whether
you appreciate produce for the long path it has traveled, for the amazing and
complex science it represents, for the consciousness it embodies, or simply
for the nutritious and delicious eating experience it delivers, once you
understand what the lifecycle of edible plants involves, it’s tough to look at
fruits and vegetables without at least a little newfound respect.
Catherine Guthrie is contributing editor of Experience Life.
Fruit-Bowl Wisdom (Back to Top)
How to properly store fruits and veggies at home. By the time fruits and veggies make it to your kitchen, they’re pretty much
in the twilight of their lives, so it’s very important to store them properly.
Some fruits and vegetables are safe to refrigerate; others should be stored on
the countertop to protect the delicate ripening enzymes. Whether they’re stored
in the fridge or on the counter, remember to keep ethylene producers (see Web
Extra! at the top right of this page) away from ripe fruits and mature vegetables so you don’t accelerate
aging. And, since moisture speeds decay, don’t wash fruits and vegetables until
you’re ready to eat them. Put paper towels between layers of berries to extend
storage time. Get more tips in “Handle With Care” in the May 2005 archives. ROOM TEMPERATURE
Store at room temperature — on the counter, in the pantry or in a drawer — and
use while fresh.
Fruits
Apples (less than 7 days),
bananas, grapefruit, lemons, limes, mandarins, mangoes, melons, oranges,
papayas, persimmons, pineapple, plantain, pomegranates, watermelons Vegetables
Basil (stems in
water), cukes+, eggplants+, garlic*, ginger, jicama, onions*, peppers
+, potatoes*, pumpkins, sweet potatoes*, tomatoes, winter squashes * Store in a well-ventilated area in the pantry. Protect potatoes from light
to avoid greening. + Can be kept in the refrigerator for one to three days, if used soon after
removal.
COUNTER TO FRIDGE
These fruits will ripen gradually on the counter, but don’t do well in
fridge for long. Refrigerate only when ripe or if cut, and not for more than a
day or two.
Fruits
Avocados,
kiwi, nectarines, peaches, pears, plums, plumcots
REFRIGERATOR
These foods spoil quickly unless kept cool. But take care not to over-cool your
fridge. Icy temperatures hasten fruits’ and veggies’ demise.
Fruits
Apples,
apricots, Asian pears, all berries, cherries, figs, grapes Vegetables
Artichokes,
asparagus, green beans, lima beans, beets, Belgian endive, broccoli, Brussels
sprouts, cabbage, carrots, cauliflower, celery, green onions,
herbs (except basil), leafy greens, leeks, lettuce, mushrooms, peas, radishes,
spinach, sprouts, summer squash, sweet corn Reproduced from Storing Fresh
Fruits and Vegetables for Better Taste by Adel
Kader,
PhD, Jim Thompson, PhD, and Kathi Sylva, PhD, University of California,
Davis, Postharvest Technology Research and Information Center, 2000.
Printed
with permission of Adel Kader, PhD.
For a detailed list of ethylene producers and ethylene-sensitive fruits and
vegetables, see the Web Extra! at the top right of this page.
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